Whole leaf and strip tobacco is commonly packed in hogsheads, cases, bales, or burlap sheets, and stored for an extended period before further processing. When the time comes for further processing, it is necessary to prepare the leaves for ready separation in conventional equipment, such as an air classifier, and this is customarily done by placing one or more of the packs of leaves in a vacuum chamber and permeating them with steam, such as by means of a sharp probe to inject the steam between layers of the leaves. As a practical matter, the use of a vacuum means that this method of separation has to be carried out on a batch basis and hence is limited in speed and efficiency compared to a continuous process. Moreover, some parts of the packed leaves are so much more dense and resistent to separation than others that localized parts of the pack remain unseparated. Such unseparated segments resist subsequent operations and thus cause difficulties in subsequent stages of operation.